Disposable irrigation gauge

Abstract

An inverted tube closely fits a supporting cup and contains a column of water. A substantially annular or ring-like space is formed between the cup and the tube. Water is fed to the annular space through a lateral opening in the tube, the upper edge of the opening being located just below the level of the cup rim. As water evaporates from the exposed ring of water, it is replaced by the inverted column, air being admitted through the tube opening. Evaporation and transpiration causes reduction of the water level thus to indicate the amount of moisture loss from the surrounding soil.

Intending to claim all novel, useful and unobvious features shown or described, I make the following claims: 
     
       1. An irrigation gauge for use in an agricultural field comprising: (a) a cup having a rim;   (b) a hollow translucent tube for containing water, said tube being closed at one end and open at the other end;   (c) means determining a fitted relationship between the cup and the open end of the tube;   (d) said tube and cup determining a space between them at the region of the cup rim for containing water exposed to the environment,   (e) said hollow tube having a lateral opening providing access for passage of air into the tube and allowing water in the tube to drop, thereby replenishing said space upon evaporation and/or transpiration of water therefrom;   (f) means cooperable with the change in the level of water in the tube to indicate the amount of moisture loss in the field.   
     
     
       2. The irrigation gauge set forth in claim 1 together with means for releasably clamping said cup to a supporting structure. 
     
     
       3. An irrigation gauge for use in an agricultural field comprising: (a) a cup extending from a base, said cup having a rim;   (b) a hollow translucent tube for containing water, said tube being closed at one end and open at the other end;   (c) said tube having, at its open end, a series of substantially equiangularly spaced protuberances extending radially outwardly and sized to provide a friction fit between the inside of the cup and the lower end of the tube, thereby to determine a substantially annular space between the cup rim and the tube containing water exposed to the environment;   (d) said tube having a lateral opening, the upper edge of which is at or below the level of the cup rim when the tube is seated in the cup, said opening providing access for passage of air into the tube and allowing water in the tube to drop, thereby replenishing water to said annular space upon transpiration or evaporation therefrom;   (e) said base having a slot cooperable with a screw for releasably clamping the cup to a supporting structure,   (f) means cooperable with the change in the level of water in the tube to indicate the amount of moisture loss in the field.